1. Field of the Invention
This invention relates generally to sterilizing trays and more specifically to cassettes adapted to support individually, operating instruments, such as dental instruments, in a sterilizing process.
2. Description of the Prior Art
In a process for sterilizing operating instruments, such as dental instruments, trays have typically been provided to individually support and retain the instruments in a separated configuration. This facilitates ease of handling and disposition within a sterilizing medium such as steam or ethylene oxide. The trays have commonly been provided with lids which are not only removably fixed to the tray but also function to lock each of the instruments in its respective supports. Both the trays and the lids have been provided with an open grate configuration to provide easy access for the sterilizing medium to contact the instruments. The trays and lids have commonly been formed from materials, such as polyethersulfone, which are stable in the presence of the sterilizing medium.
Of particular interest to the present invention is the means by which the lids have been removably fixed to the trays. End walls of the trays have extended from a bottom upwardly to a lip or handle which has extended generally horizontally in a top plane of the tray. Central portions of each end wall and the handle have been vertically slit to form a center support at each end of the tray. The purpose of the vertical slits has been to weaken the center supports so that they can be bent out of the plane of the sidewalls. Slots have been formed in the center supports and positioned to register with tabs on the ends of the lid.
The tabs have been fixed with respect to the lid and positioned to register with the slots when the center supports are in their normal position. Only by bending these center supports out of their normal position has it been possible to lock and unlock the lids with respect to the trays.
Unfortunately the weakening of the end walls, which is necessary to provide the center supports with bendable characteristics, has also made these supports susceptible to breaking. Attempts have been made to stiffen the supports so that they can be less breakable, but this has only resulted in making it more difficult to lock and unlock the lids with respect to the trays. What is required is a simple locking mechanism which can be operable with little force without weakening the walls of the tray.